Websites like GoodRx.com and LowestMed.com have been created so consumers can hunt for the best deal among local pharmacies and print coupons.

A recent search for a 30-day supply of Lipitor on GoodRx found the drug’s cost ranged from free at Meijer to $75 after a coupon at CVS.

Antonio Ciaccia, director of Government and Public Affairs for the Ohio Pharmacy Association, said the answer to this puzzle, lies in the negotiating that goes on behind the scenes between pharmacies and pharmacy benefit managers — middlemen who work on behalf of health insurance plans.

Pharmacy benefit managers negotiate the rate at which they reimburse pharmacies for different drugs and therefore negotiate lower prices at some chains than others. CVS Health is both a pharmacy benefit manager and owner of a large chain of pharmacies, so drugs may be more or less expensive at CVS stores depending on the deals the benefit manager arm has cut with drug makers.

A patient’s health plan may require they pay full price for drugs if they go to an “out-of-network” or “not preferred” pharmacy. What’s out-of-network may be based on which pharmacy benefit manager the plan contracts with.

In addition, pharmacies add markups to the drugs they sell in order to make a profit, and can change that amount based on how much they expect to get reimbursed from health plans for that specific drug.

The large PBMs also own their own mail-order pharmacies.

“Mail-order and PBM policies try to steer patients toward mail order because obviously then they can reap the benefit on the PBM side and the mail-order side,” Ciaccia said.

A spokesman for Express Scripts, which owns an online pharmacy business in addition to its large business as a pharmacy benefit management company, said mail-order operations, through automation, have been shown to be more efficient and make less potentially deadly errors.